FIG. 1 is a cross-sectional view of a conventional turbomachine 100, illustrated as a centrifugal compressor, including labyrinth seals 101. As illustrated, the labyrinth seals 101 may be disposed about rotor components (e.g., impellers 102) of the turbomachine 100. Additional labyrinth seals 103 may be disposed about other rotor components (e.g., a rotary shaft 104) of the turbomachine 100. An inner circumferential surface 105 of the labyrinth seals 101, 103 and an outer circumferential surface 107 of the rotor components (e.g., the impellers 102 and the rotary shaft 104), referred to herein as the rotor 102, 104, may define a radial gap or clearance 109 therebetween. The distance between the labyrinth seals 101, 103 and to the rotor 102, 104 may be adjusted (i.e., increased or decreased) to increase or decrease the radial gap 109 defined therebetween and thereby control leakage of a process fluid across the labyrinth seals 101, 103.
Conventional methods for adjusting the distance between the labyrinth seals 101, 103 and the rotor 102, 104 to increase or decrease the radial gap 109 in the turbomachine 100, however, often require that the existing labyrinth seals 101, 103 be removed and replaced with another labyrinth seal. The removal and replacement of the labyrinth seals 101, 103 may be both time consuming and costly. For example, to remove and replace the labyrinth seals 101, 103, the turbomachine 100 is typically at least partially disassembled to obtain access to the labyrinth seals 101, 103. Further, additional labyrinth seals that may provide the desired radial gap 109 must be readily available to replace the labyrinth seals 101, 103.
What is needed, then, is a labyrinth seal capable of varying the distance between the labyrinth seal and the rotor to thereby vary the radial gap in a turbomachine.